May weather in Cortland, IL
The average temperature in Cortland in May is 59.7°F (49.2°F–70.2°F). Average precipitation: 4.79 inches.
May is a spring month in Cortland, and is warmer than the annual average of 48.5°F. Daily temperatures swing about 21°F between overnight low and afternoon high. Expect about 13 days with precipitation. Daylight averages about 14h 22m. For travel, May is a comfortable month to visit.
Avg High
70.2°F
Avg Low
49.2°F
Precipitation
4.79 in
Daylight
14h 22m
May records in Cortland
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| May 1 | 84.9°F (2013) | 28.0°F (1978) | 2.27 in (2003) |
| May 2 | 90.0°F (1992) | 28.9°F (1966) | 0.86 in (1983) |
| May 3 | 84.0°F (2021) | 27.0°F (2005) | 1.94 in (2018) |
| May 4 | 86.0°F (1980) | 28.9°F (2005) | 1.47 in (1990) |
| May 5 | 87.1°F (1980) | 30.0°F (1987) | 1.53 in (1977) |
| May 6 | 84.9°F (2000) | 28.0°F (1989) | 2.17 in (1976) |
| May 7 | 86.0°F (2004) | 24.1°F (1989) | 1.03 in (1972) |
| May 8 | 87.1°F (2023) | 30.9°F (1989) | 1.51 in (1998) |
| May 9 | 88.0°F (2014) | 27.0°F (1966) | 1.12 in (1995) |
| May 10 | 87.1°F (1993) | 25.0°F (1966) | 1.54 in (1990) |
| May 11 | 91.0°F (2011) | 28.0°F (1989) | 1.25 in (2005) |
| May 12 | 91.9°F (2011) | 30.0°F (1981) | 2.58 in (1978) |
| May 13 | 91.9°F (2022) | 32.0°F (2021) | 2.41 in (2010) |
| May 14 | 91.0°F (2022) | 35.1°F (1988) | 1.15 in (2020) |
| May 15 | 93.0°F (2013) | 34.0°F (2016) | 2.52 in (2020) |
| May 16 | 93.0°F (2025) | 32.0°F (2014) | 0.93 in (1974) |
| May 17 | 88.0°F (1977) | 33.1°F (2014) | 1.50 in (1974) |
| May 18 | 90.0°F (1987) | 33.1°F (2002) | 1.87 in (1986) |
| May 19 | 93.9°F (1975) | 34.0°F (2002) | 1.10 in (1987) |
| May 20 | 93.9°F (1975) | 35.1°F (1981) | 1.40 in (1998) |
| May 21 | 90.0°F (2012) | 30.9°F (2002) | 2.81 in (2004) |
| May 22 | 91.0°F (1975) | 34.0°F (2006) | 2.59 in (1983) |
| May 23 | 91.0°F (1975) | 35.1°F (1969) | 1.17 in (1995) |
| May 24 | 91.0°F (2010) | 36.0°F (1992) | 1.52 in (1995) |
| May 25 | 91.9°F (2010) | 30.0°F (1988) | 1.14 in (1975) |
| May 26 | 95.0°F (1985) | 36.0°F (1979) | 1.55 in (2011) |
| May 27 | 93.0°F (1985) | 30.0°F (1992) | 1.43 in (1973) |
| May 28 | 96.1°F (2012) | 33.1°F (1992) | 1.07 in (1995) |
| May 29 | 93.0°F (2006) | 35.1°F (1984) | 2.59 in (1996) |
| May 30 | 93.0°F (2006) | 35.1°F (2021) | 1.96 in (2011) |
| May 31 | 91.0°F (1994) | 41.0°F (2015) | 2.61 in (2004) |